Intelligent Design Fan DaveScot Demonizes Chance

I started reading Lenski’s full paper myself to see what raw data was provided and I got no farther than the first paragraph beyond the abstract when I encountered a bias error that a chance worshipper (sic) would never notice. My emphasis:

At its core, evolution involves a profound tension between
random and deterministic processes. Natural selection
works systematically to adapt populations to their prevailing
environments. However, selection requires heritable variation
generated by random mutation, and even beneficial mutations
may be lost by random drift. Moreover, random and deterministic
processes become intertwined over time such that future
alternatives may be contingent on the prior history of an evolving
population.

The bold portion is patently wrong. Selection operates on any heritable variation whether random or not. That the authors would use the language they did (random variation) and the peer reviewers didn’t notice it is testimony to the chance worshipper (sic) bias that pervades evolution
research.

In case you missed him repeating it for emphasis, DaveScot has recently begun to refer to scientists as “chance worshipers,” proving that if you can’t argue on par with someone, your best fallback is to ridicule them with cutesy names that belittle their arguments by implying that they are mere dogma.

But why is it that scientists like Lenski so often speak of “random” mutation? Because that’s exactly what they observe when they look at how variation emerges in genomes over time. While it’s true that selection could, in theory, work on non-randomly selected traits, that’s just not what we see happening in practice, and not particularly relevant to what Lenski is describing in any case. In fact, the whole point of Lenski’s paper is about the power of contingency: the way even random events open or close doors of possibility.

Part of the problem, perhaps, is that DaveScot doesn’t quite understand what scientists mean by “random” in this context. No biologist literally means that events like mutations occur with no causal explanation: that literally anything can happen to anything. What they mean is that the mutations that do occur, caused by all sorts of different processes, copying errors, and so on, are not correlated in any observable way with the outcomes they generate.

This misunderstanding quickly gets DaveScot into trouble when he tries to provide evidence that mutation isn’t random:

The Scripps researchers, in a nutshell, discovered that E. coli, when stressed (such as running out of food as in Lenski’s experiment or in the presence of antibiotics in the Scripps experiment) selectively increases the mutation rate on certain genes. Thus the mutations in this case are not random but rather directed at a certain area in an attempt to solve a certain problem.

But the paper in question does not, in fact, suggest that the mutations in question aren’t random. What it describes is a particular mechanism E. Coli have for essentially inducing more copying error (reducing the fidelity of inherited traits) in response to environmental pressures. There’s no evidence that the E Coli. are actually specifically choosing certain mutations over others based on any foreknowledge of whether those mutations will be beneficial or not. All they’re doing is tossing the dice more often on a particular set of genes.

And while the fact that a particular set of genes is singled out for modification is certainly interesting an interesting feature (though not unlike many other genetic known features that conserve certain parts of the genome), it’s still just a mechanism within the E Coli. itself, not a mark of intelligent intervention, intelligence, or foreknowledge.

Well, that’s because unlike scientists, creationists aren’t looking for the truth. They are *defending* the truth as they believe it to be, acording to their religious beliefs and dogma. Many’s the skeptic who ended up banging his or her head against the wall because a creationist couldn’t accept what seems so clear. This is because it is exceedingly difficult to employ evidence, facts, science, logic, reason, etc., to change beliefs that weren’t formed by logic, reason, evidence, etc., in the first place. And that’s just the sincere-but-woefully-wrong believers. Advocative creationists actively and knowingly obfuscate, confuse, and otherwise mangle the evidence for evolution in defense of what they feel is their already held truths concerning evolution, speciation, etc.

Grendel: Sweeping generalizations are bound to be untrue, no matter who makes them. Most creationists I’ve met actually are interested in the truth but are just extremely underinformed. In most cases, everyone they have ever respected was a creationist, and they’ve never met someone who presented them with a significant amount of evidence in a clear way. I’ve also known creationists who changed their minds after their first bio class in college. Though there does seem to be a different demographic when you just look at commenters on blogs.

Point well taken, Pat. I shouldn’t have generalized about ‘all creationists’. When I did I was in fact thinking about the media-seeking advocative sort, the most of whom I’m convinced are well aware they’ve no leg to stand on and seek only to obfuscate and confuse things, not for evolutionists or skeptics, but for the people who consume their media. A good example is Egnor, who Dr. Novella has been debating of late. I think it’s no accident his site has no comments section so the only voice his readers see is his own. But thanks for pointing that out.

~*~

For religious believers, from creationists and fundies on down, changing beliefs involves far more than, um, changing beliefs. I think their respective sets of beliefs spread far wider and deeper in their lives than the tentatively held beliefs of the scientist or science-minded people do in their lives. The science-minded are prepared to change their beliefs when the evidence compels it, and those beliefs aren’t likely to involve so much of the other areas of life as it does for the religious believer. If a religious person comes to drop belief in God or in God’s ‘works’ it could change everything for them, including what they do every Sunday morning. If new evidence came along that changed some fundamental scientific holding (I struggle to think of an example) I’d change my beliefs accordingly, but it wouldn’t change much else in my life. If my premise is true, it must make changing beliefs much harder for the religious than simply reading the new evidence and adjusting accordingly.

Creationists think they are defending God, but they are only defending one interpretation of God (the God who created the world in 7 days). They have difficulty accepting that evolution could have been the mechanism for God to create the world.

It could also have been the mechanism for the Flying Spaghetti Monster to create the world. ‘Could’ doesn’t count for much. Evidence does.

Besides, evolution has absolutely nothing to do with the creation of the world. Evolution explains speciation, the origins of new species. Evolution purports nothing about biogenesis, the beginning of life on Earth, and nothing about the creation or formation of the Earth.

An important point you make in your post is that selection pressure increases the rate of mutation on certain genes. I’ve not heard that before. Is this what is really happening or is this based on hindsight. That is, of the organisms that survive under a certain selection pressure, we can readily see an increased mutation rate in specific genes. If there is no design or foreknowledge, then shouldn’t mutation rate be the same across all genes?

It may mean that mutation rates are variable and when species are pressured, those with the highest rate of mutations are more likely to experience mutation(s) which alleviate the pressure before extinction may occur.

I can see how selection pressure acts as a filter for genes with higher mutation rates, though there must be something about them that makes it easier for these particular genes to have copying errors, deletions, insertions, etc. Of course, not being an expert in such matters, there may in fact be a characterization of these “traits” that I’m not aware of.

So, I’m just trying to get at the mechanism behind “inducing” in “What it describes is a particular mechanism E. Coli have for essentially inducing more copying error (reducing the fidelity of inherited traits) in response to environmental pressures.” Selection pressure filtering may be all that is meant.

skepTick: It could be any one of a number of possibilities as to how certain genes became favored sites for modification in certain environments. I’m not sure the scientists in this case know exactly which of the possibilities was true in this case: doing things like that is very hard in the case of a bacterium simply sitting there as is in the lab: we have little real historical evidence to work with in that case with which to rule out some possibilities so as to make some more certain.

It’s pretty common, on the other hand for sectors that have high mutation rates to be somehow involved in chemical interactions that work sort of like a lock and key. For instance, abalone sperm and eggs have such a system, and the general chemical code for abalone sperm to enter another abalone’s eggs is shifting all the time, which occasionally creates speciation events based purely on some populations lock/key drifting away from others. A high mutation rate along these lines could get selected for based on its ability to break into other pockets of “locks” by chance, and hence found new lines of abalone that most other ablaone are “locked out” of.